frostat in outdoor boiler unit setting

Andy From Sligo

what recommendation setting for frostat in outdoor grant metal oil boiler ?

was on 4c but could i safely go down to 2c or even 0c? - just want to eeek as much oil out in the winter and I remember last winter it coming on in the night when it wasnt even freezing outside and the time clock was off..

jimf

leave it at zero

because it could be -5 outside cabinet

Pete67

Also the frost stat should be wired via a normally closed contact of a pipe stat installed on the return close to the boiler. Set the pipe stat to around 30 degrees. Then the boiler will only cycle on and off sufficiently to keep the system warm in freezing weather rather than heat your house continuously when the outside temp is below freezing.

Andy From Sligo

Pete67 wrote: »

Also the frost stat should be wired via a normally closed contact of a pipe stat installed on the return close to the boiler. Set the pipe stat to around 30 degrees. Then the boiler will only cycle on and off sufficiently to keep the system warm in freezing weather rather than heat your house continuously when the outside temp is below freezing.

you reckon a pipe stat as well as the frost-stat then? - thing is when the timer is off at night that also turns off the water circulation pump in the boiler as well, although I know if the frost-stat is on a permanent live bypassing the clock/timeswitch live and that when the frost-stat kicks in it also initiate the pump (on the return pipe in my particular setup in our boiler module and not on the flow pipe)

So what you are suggesting is put a pipe-stat on the return pipe connected to the CH pump that only feeds live to the pump when the temperature of the water heats in the pipe to 30 degrees c and over - is that what you are suggesting? so no circulating pump working until the water in the boiler has heated up to at least 30c ?

Pete67

No. Just take the switched live from the frost stat through the pipe stat and then on to the boiler. So when the outside temp drops below freezing, the boiler fires and runs only until the return temp reaches 30c and then it stops.

Without the pipe stat the frost stat will cause the boiler to heat the house continuously when the weather is freezing, which is very wasteful.

Andy From Sligo

I'd be surprised if even when the outside of the grant module the temp if it ever goes down to 0'c freezing outside that it would be freezing inside the module/housing because its so well insulated with loft insulation and the tin foil stuff on top . Even if it did it would get up past 0'c so quickly that it wouldnt even have time to circulate through the radiator would it?

Andy From Sligo

jimf wrote: »

leave it at zero

because it could be -5 outside cabinet

torn now jim because i just been reading instructions for Vortex outdoor boiler unit and it says its fitted with a (nonadjustable ... but i bet its adjustable with the cover off) frostat in the unit factory set at 5c

Think I might go out and set it back to 4/5c ... its would still have to be pretty freezing outside to turn it on wouldnt it? -

DGOBS

Jazus, Andy your the Steve Erwin of DIY........remember what eventually happened to him! Manufacturer in their wisdom decided on 5º for a reason, Stephen Grant is a very intelligent and considered man, trust him, after all you bought his product!

agusta

Andy From Sligo wrote: »

torn now jim because i just been reading instructions for Vortex outdoor boiler unit and it says its fitted with a (nonadjustable ... but i bet its adjustable with the cover off) frostat in the unit factory set at 5c

Think I might go out and set it back to 4/5c ... its would still have to be pretty freezing outside to turn it on wouldnt it? -

The frost stat cant be adjusted in the grant vortex.they used to be set at 3 to 5 degrees. now they are preset at 2 degrees approx. water starts to expand at 4 degrees

Andy From Sligo

DGOBS wrote: »

Jazus, Andy your the Steve Erwin of DIY........remember what eventually happened to him! Manufacturer in their wisdom decided on 5º for a reason, Stephen Grant is a very intelligent and considered man, trust him, after all you bought his product!

1st of all 'I' didnt buy his product haha

secondly i wont be going deep sea diving any time this century

but thank you for your reply thats very helpful (I think) so (without wishing to put words in your mouth) are you saying that its factory set for a reason and that 5c is the correct setting to leave on the frost stat?

Vronsky

Andy From Sligo wrote: »

1st of all 'I' didnt buy his product haha

secondly i wont be going deep sea diving any time this century

but thank you for your reply thats very helpful (I think) so (without wishing to put words in your mouth) are you saying that its factory set for a reason and that 5c is the correct setting to leave on the frost stat?

It is set to 5C because water starts to expand below 4C.

DGOBS

Hi Andy, yes it's set at that for a reason, there's no need to change it unless it's causing an issue.

If you were ever going deep sea diving, I can just imagine you fiddling with the air regulators just before you did...:D

Love how curious you are about everything, but say your a nightmare to live with!!:eek:

Your one in a million mate.

Andy From Sligo

DGOBS wrote: »

Hi Andy, yes it's set at that for a reason, there's no need to change it unless it's causing an issue.

If you were ever going deep sea diving, I can just imagine you fiddling with the air regulators just before you did...:D

Love how curious you are about everything, but say your a nightmare to live with!!:eek:

Your one in a million mate.

yeah, I can't even live with meself sometimes

Andy From Sligo

Vronsky wrote: »

It is set to 5C because water starts to expand below 4C.

ah right thank you - shall leave it on 5c from now on then, cheers

jimf

andy isn't there a new phone out shortly that needs dissecting that should keep you quite for a few weeks

oh on second thoughts maybe not

Andy From Sligo

Pete67 wrote: »

Also the frost stat should be wired via a normally closed contact of a pipe stat installed on the return close to the boiler. Set the pipe stat to around 30 degrees. Then the boiler will only cycle on and off sufficiently to keep the system warm in freezing weather rather than heat your house continuously when the outside temp is below freezing.

ok i have done one of my famous drawings to what I think you mean. After doing the drawing though I looked at it and thought "I have got the Frost stat and the pipe stat the wrong way round havent I?" - permanent live should go through frost-stat first and then pipe stat and then onto Burner&Pump live shouldnt it?

Tom44

Offs
Get in the bomb shelter

Andy is dangerous.

Andy From Sligo

Tom44 wrote: »

Offs
Get in the bomb shelter

Andy is dangerous.

ah sure whats the worst it will do, freeze or blow a fuse sure

Dtp1979

Andy From Sligo wrote: »

ok i have done one of my famous drawings to what I think you mean. After doing the drawing though I looked at it and thought "I have got the Frost stat and the pipe stat the wrong way round havent I?" - permanent live should go through frost-stat first and then pipe stat and then onto Burner&Pump live shouldnt it?

Do you pay for all these alterations yourself Andy or get the landlord?

Andy From Sligo

Dtp1979 wrote: »

Do you pay for all these alterations yourself Andy or get the landlord?

its all surmising, and playing around with ideas and getting others ideas at the moment my friend ...

i hate to to see things not done properly

K.Flyer

Andy From Sligo wrote: »

its all surmising, and playing around with ideas and getting others ideas at the moment my friend ...

i hate to to see things not done properly

So now you are saying that Grant Engineering don't know how to do things properly.
I don't mean to sound harsh, but they are considered to be the best oil boiler on the Irish market, what makes you think with your very limited experience that you know better. :rolleyes:

Pete67

Andy, for an outdoor unit in a cabinet, where the frost stat is inside the cabinet as part of the boiler package, the pipe stat is not required, as the frost stat will open once the temperature inside the cabinet rises above 5 degrees. So the boiler will not run continuously in freezing conditions.

If the boiler is in a separate boiler house, where the frost stat may be some distance from the boiler, or even mounted on an external wall, then interlocking the frost stat with a return pipe stat is a good idea as it prevents the boiler running continuously in freezing conditions, while providing adequate protection against freezing and burst pipes.

For indoor boilers, a frost stat may not be required, a fixed (non adjustable) room stat set at 10 degrees may be a better option. This keeps the building structure above 10 degrees and prevents building fabric damage due to damp, condensation etc when the building is unoccupied, in addition to protecting the heating system from frost damage. Consideration must be given to opening zone valves as required if this system is adopted, so the control wiring can get complex fairly quickly. This approach is often used in commercial buildings where it is easily implemented via the BMS system.

I suppose my point is that there is no one size fits all, and the heating system controls should be designed to suit the individual system and type of building etc. I do agree that this is often not done well in domestic installations, however I don't think you need to worry about a packaged outdoor boiler unit such as your Grant boiler, as it has already been taken care of adequately. Hope that helps and keep asking the questions!

Andy From Sligo

K.Flyer wrote: »

So now you are saying that Grant Engineering don't know how to do things properly.
I don't mean to sound harsh, but they are considered to be the best oil boiler on the Irish market, what makes you think with your very limited experience that you know better. :rolleyes:

no - you are putting words in my mouth .

I think they are exemplary and make very good products -

There is no AAV in the return pipe in my EuroFlame condensing boiler module - and i think they could have fitted it at factory level as indicated in the instruction book , or maybe the installer should have fitted one at fitting time.

The Frost-stat as I see it should have been a non adjustable type (but maybe the installer put a adjustable type on it at time of fitting)

The Cotherm boiler stat with overheat (that I presumed Grant fitted, not the installer) packed up shortly after using the boiler resulting in the boiler overheating. They should have just carried on using the IMMIT ones (and the IMMIT ones had the centigrade numbers stamped on them which were better)

Andy From Sligo

Pete67 wrote: »

Andy, for an outdoor unit in a cabinet, where the frost stat is inside the cabinet as part of the boiler package, the pipe stat is not required, as the frost stat will open once the temperature inside the cabinet rises above 5 degrees. So the boiler will not run continuously in freezing conditions.

If the boiler is in a separate boiler house, where the frost stat may be some distance from the boiler, or even mounted on an external wall, then interlocking the frost stat with a return pipe stat is a good idea as it prevents the boiler running continuously in freezing conditions, while providing adequate protection against freezing and burst pipes.

For indoor boilers, a frost stat may not be required, a fixed (non adjustable) room stat set at 10 degrees may be a better option. This keeps the building structure above 10 degrees and prevents building fabric damage due to damp, condensation etc when the building is unoccupied, in addition to protecting the heating system from frost damage. Consideration must be given to opening zone valves as required if this system is adopted, so the control wiring can get complex fairly quickly. This approach is often used in commercial buildings where it is easily implemented via the BMS system.

I suppose my point is that there is no one size fits all, and the heating system controls should be designed to suit the individual system and type of building etc. I do agree that this is often not done well in domestic installations, however I don't think you need to worry about a packaged outdoor boiler unit such as your Grant boiler, as it has already been taken care of adequately. Hope that helps and keep asking the questions!

ah right thanks for that Pete - I got my wires crossed then (excuse the pun ) - I thought you mean that as well as a frost-stat in the outdoor module it would need a pipe stat as well so that when the frost stat kicked in that it wouldnt go to the rads/immersion coil and that the hot water stay in the boiler/boiler house.

Thanks for that, shall leave it like that then with just protected by Frost-stat. It did kind of made sense though because as you said when the frost-stat starts up it also runs the pump and of course that hot water would run out of the boiler and onto the rads and immersion cylinder. so it would have made sense to run the burner but not run the pump until 30c just so it would heat up the inside of the outdoor unit and not distribute the hot water to the rads/immersion tank.

Its just last year in winter with it set to 5c (its an adjustable stat in there) I was thinking I could hear it start up quite a lot in the night thats why I was asking on her could I reduce it lower than 5c - of course also it might not have even been our boiler keep starting up , it might have been someone elses because we live on a housing estate.